Band-pass and band-rejection filters have been widely used to control the flow of signals that propagate in electronic circuits. A band-pass filter is an electrical filter that allows a band of frequencies comprising a signal to pass through the circuit with minimal loss. A band-rejection (band stop) filter, on the other hand, is an electrical filter that rejects or suppresses a band of frequencies.
Resonators are essential components found in filter devices. Conventional resonators frequently utilize air gaps in their structure. However, resonators can be built with ferrites to improve their loss characteristics. Resonators having ferrite components may be built in several configurations. Given a similar geometrical structure, it is a perspective view of a filter device utilizing a single resonator possible to obtain different propagation characteristics in ferrites by using different bias configurations.